fix(email): preserve personalization tokens for template rendering

packages/email-renderer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/email-renderer",
-  "version": "0.1.22",
+  "version": "0.1.23",
   "type": "module",
   "description": "WRNexus block email renderers with HTML, text, AMP Email, and MJML interoperability.",
   "exports": {

packages/email-renderer/src/email.ts

@@ -110,6 +110,8 @@ export async function renderEmail(
     direction?: "ltr" | "rtl";
     variables?: Record<string, unknown>;
     requireVariables?: boolean;
+    /** Preserve allowlisted tokens and fallbacks for template export, never for final delivery. */
+    preserveVariables?: boolean;
     countdownImageUrl?: string;
     /** Trusted host injection; never sourced from the editable document. */
     ampValidator?: (content: string) => Promise<ValidationReport>;
@@ -118,6 +120,7 @@ export async function renderEmail(
 ): Promise<Result<EmailRenderBundle>> {
   const personalized = resolveDocumentVariables(document, emailKind.variables, options.variables, {
     requireValues: options.requireVariables,
+    preserveTokens: options.preserveVariables,
   });
   if (!personalized.ok) return personalized;
   if (options.countdownImageUrl) {

packages/email-renderer/test/template-variables.test.ts

@@ -0,0 +1,32 @@
+import { expect, test } from "bun:test";
+import { resolveDocumentVariables, type BlockDocument } from "@wrnexus/blocks";
+import { renderEmail } from "../src/index.ts";
+
+const document: BlockDocument = {
+  schemaVersion: 1, kind: "email", meta: { subject: "Hi {{recipientName|friend}}", lang: "en" },
+  theme: { tokens: {} },
+  root: { id: "root", type: "layout.email-document", version: 1, props: {}, styles: {}, slots: {
+    content: [{ id: "text", type: "content.text", version: 1, props: { text: "Hello {{recipientName|friend}}" }, styles: {}, slots: {} }],
+  } },
+};
+
+test("template rendering preserves fallback tokens rather than baking in sample or fallback values", async () => {
+  const before = structuredClone(document);
+  const rendered = await renderEmail(document, { preserveVariables: true, mjml: true, variables: { recipientName: "Preview only" } });
+  expect(rendered.ok).toBe(true);
+  if (!rendered.ok) return;
+  expect(rendered.value.subject).toBe("Hi {{recipientName|friend}}");
+  expect(rendered.value.parts.html.content).toContain("Hello {{recipientName|friend}}");
+  expect(rendered.value.parts.text.content).toContain("Hello {{recipientName|friend}}");
+  expect(rendered.value.exports?.mjml).toContain("Hello {{recipientName|friend}}");
+  expect(document).toEqual(before);
+  const resolved = await renderEmail(document, { variables: { recipientName: "Ada" }, requireVariables: true });
+  expect(resolved.ok && resolved.value.subject).toBe("Hi Ada");
+});
+
+test("preservation still validates token allowlists and cannot masquerade as resolved delivery", () => {
+  const unknown = structuredClone(document);
+  unknown.meta.subject = "{{unregistered}}";
+  expect(resolveDocumentVariables(unknown, { recipientName: "string" }, {}, { preserveTokens: true }).ok).toBe(false);
+  expect(resolveDocumentVariables(document, { recipientName: "string" }, {}, { preserveTokens: true, requireValues: true }).ok).toBe(false);
+});